A young lad with acute lymphocytic leukemia (ALL) shows up to your ED feeling very weak and c/o sever muscle cramps. On further questioning he reveals that he started chemotherapy 3 days ago. Labs show potassium of 6.5 mEq/L, calcium of 6.3 mg/dl and a creatinine of 11.1 mg/dL. How are you going to help this lad?
ANSWER: He need emergent hemodialysis and aggressive hydration.
Our patient is suffering from tumor lysis syndrome (TLS) causing multiple electrolyte and metabolic abnormalities requiring dialysis. As shown in the diagram below, TLS occurs secondary to increased cell death (caused by chemotherapy) in a rapidly growing tumor. Time frame to onset is hours to a few days after the initiation of chemotherapy or radiation therapy. TLS is commonly seen in hematologic malignancies (ALL, non-Hodgkin’s lymphomas) and in some solid tumors like small-cell lung carcinoma. Symptoms can be non-specific, usually reflecting primary electrolyte abnormalities. With hyperkalemia, ECG changes are common and can be exacerbated by concomitant hypocalcemia. Hyperphosphatemia and hyperuricemia are also commonly seen. Kidney function is a critical factor in the development and treatment of metabolic abnormalities as it is responsible for the removal and resorption of the various electrolytes involved. Initial therapy should be with stopping chemotherapy and/or radiation and starting fluids. Further care depends on the electrolyte abnormalities present. With severe metabolic derangements, hemodialysis is required.
The indications for hemodialysis in TLS:
- serum K 6 mEq or above
- serum uric acid 10 mg/dL or above
- serum creatinine 10 mg/dL or above
- serum phosphorus 10 mg/dL or above (or rapidly rising)
- volume overload on clinical exam
- symptomatic hypocalcemia (paresthesias, tetany, palpitations etc)
References
Ugras-Rey S, Watson M: Selected Oncologic Emergencies, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 121: p 1590-1613
